From fb7669b5a0695922a9813bb103303db3d7c79c8d Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Tue, 23 Apr 2013 10:53:18 -0400 Subject: Btrfs: don't BUG_ON() in btrfs_num_copies A user sent me a btrfs-image that was panicing because of some corruption. This is because we pass in a bogus value to btrfs_num_copies, and it panics. Instead just return 1. We only call btrfs_num_copies to see if there are other copies to try and read for things, so if we just return 1 it will make the callers exit out with an appropriate error value. Thanks, Signed-off-by: Josef Bacik --- fs/btrfs/volumes.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) (limited to 'fs/btrfs') diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index c8a315d..c1a2217 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -4232,9 +4232,25 @@ int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len) read_lock(&em_tree->lock); em = lookup_extent_mapping(em_tree, logical, len); read_unlock(&em_tree->lock); - BUG_ON(!em); - BUG_ON(em->start > logical || em->start + em->len < logical); + /* + * We could return errors for these cases, but that could get ugly and + * we'd probably do the same thing which is just not do anything else + * and exit, so return 1 so the callers don't try to use other copies. + */ + if (!em) { + btrfs_emerg(fs_info, "No mapping for %Lu-%Lu\n", logical, + logical+len); + return 1; + } + + if (em->start > logical || em->start + em->len < logical) { + btrfs_emerg(fs_info, "Invalid mapping for %Lu-%Lu, got " + "%Lu-%Lu\n", logical, logical+len, em->start, + em->start + em->len); + return 1; + } + map = (struct map_lookup *)em->bdev; if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1)) ret = map->num_stripes; -- cgit v1.1